From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:49238 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752968AbdKCQeq (ORCPT ); Fri, 3 Nov 2017 12:34:46 -0400 Date: Fri, 3 Nov 2017 17:34:44 +0100 From: Petr Janecek To: linux-btrfs@vger.kernel.org Subject: btrfs_cleaner lockdep warning in v4.9.56 Message-ID: <20171103163443.GA30483@atrey.karlin.mff.cuni.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hello, this warning happened during "btrfs subvolume remove" of a readonly snapshot after the newest in the snapshot series was "btrfs received". [96857.000284] ------------[ cut here ]------------ [96857.000307] WARNING: CPU: 1 PID: 371 at kernel/locking/lockdep.c:704 register_lock_class+0x4c8/0x530 [96857.000322] Modules linked in: fuse vfat msdos fat dm_mod nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc xfs ipmi_watchdog libcrc32c raid1 iTCO_wdt iTCO_vendor_support x86_pkg_temp_thermal coretemp kvm_intel kvm evdev irqbypass serio_raw hpilo hpwdt tpm_tis tpm_tis_core acpi_power_meter tpm button lpc_ich mfd_core md_mod ipmi_si ipmi_poweroff ipmi_devintf ipmi_msghandler autofs4 btrfs xor raid6_pq sg sd_mod uas usb_storage crc32c_intel ahci libahci psmouse libata scsi_mod uhci_hcd xhci_pci xhci_hcd tg3 ptp pps_core libphy thermal ehci_pci ehci_hcd usbcore usb_common [96857.000744] CPU: 1 PID: 371 Comm: btrfs-cleaner Not tainted 4.9.56 #13 [96857.000769] Hardware name: HP ProLiant MicroServer Gen8, BIOS J06 06/06/2014 [96857.000795] ffffc90000a4fa48 ffffffff81309da5 0000000000000000 0000000000000000 [96857.000849] ffffc90000a4fa88 ffffffff81059b7c 000002c000000004 0000000000000000 [96857.000901] 0000000000000000 ffffffff8234baf0 ffff880041fca450 0000000000000000 [96857.000954] Call Trace: [96857.000979] [] dump_stack+0x67/0x92 [96857.001004] [] __warn+0xcc/0xf0 [96857.001029] [] warn_slowpath_null+0x18/0x20 [96857.001054] [] register_lock_class+0x4c8/0x530 [96857.001080] [] __lock_acquire+0x76/0x7f0 [96857.001105] [] lock_acquire+0xbe/0x1f0 [96857.001161] [] ? btrfs_tree_lock+0x89/0x250 [btrfs] [96857.001188] [] _raw_write_lock+0x33/0x50 [96857.001233] [] ? btrfs_tree_lock+0x89/0x250 [btrfs] [96857.001276] [] btrfs_tree_lock+0x89/0x250 [btrfs] [96857.001322] [] ? find_extent_buffer+0xda/0x1e0 [btrfs] [96857.001367] [] ? release_extent_buffer+0xc0/0xc0 [btrfs] [96857.001409] [] do_walk_down+0xf0/0x930 [btrfs] [96857.001450] [] walk_down_tree+0xb2/0xe0 [btrfs] [96857.001491] [] btrfs_drop_snapshot+0x3a9/0x780 [btrfs] [96857.001517] [] ? _raw_spin_unlock+0x22/0x30 [96857.001561] [] ? btrfs_kill_all_delayed_nodes+0xbd/0xd0 [btrfs] [96857.001617] [] btrfs_clean_one_deleted_snapshot+0xad/0xe0 [btrfs] [96857.001672] [] cleaner_kthread+0x16f/0x1e0 [btrfs] [96857.001713] [] ? btree_invalidatepage+0xa0/0xa0 [btrfs] [96857.001741] [] kthread+0x116/0x130 [96857.001765] [] ? kthread_park+0x60/0x60 [96857.001790] [] ret_from_fork+0x27/0x40 [96857.001814] ---[ end trace ff21435da4cc1bc5 ]--- Regards, Petr